Introduction

This guide is intended to provide a comprehensive description of the
encounter with Yor'sahj the Unsleeping in Dragon Soul. It is targeted at anyone
who desires to understand the fight mechanics.

This guide is updated for World of Warcraft WoD 6.1.2.

Yor'sahj the Unsleeping is one of the two bosses that are unlocked after
defeating Morchok, in the Dragon Soul raid. He is a Faceless One that your
raid will fight in one of two very similar Old God themed rooms, outside of
Wyrmrest Temple.

The encounter mechanics present a great deal of originality. The raid leader
will be doing most of the job by giving the raid the right instructions.
Then, the fight will be most taxing for DPS players and healers.

1. General Information

1.1. Health Pool

Difficulty

Yor'sahj

Oozes

Mana Void

Forgotten Ones

10-man

47M

1.8M

1.5M

490k

10-man Heroic

90M

2.5M

2M

830k

25-man

142M

5.4M

5M

1.5M

25-man Heroic

232M

8.2M

6.5M

2.7M

LFR

106M

4.1M

3.8M

1.1M

1.2. Enrage Timer

Yor'sahj the Unsleeping has a 10 minute enrage timer in all difficulties.

3. Overview of the Fight

The Yor'sahj encounter is essentially a single phase fight. The encounter
is unique, in the sense that Yor'sahj has only one ability, which he casts with
regularity.

In addition, approximately every 75 seconds, Yor'sahj will summon 3 random
oozes of a different type (out of 6 possible types). Upon reaching the boss,
each ooze buffs the boss, granting him a
specific ability that is temporary and lasts 60 seconds. When there are
15 seconds left on his buffs, the boss begins summoning the next set of
3 oozes.

Your raid can only kill one of the three oozes each time (as soon as one
dies, the other two become immune), so the challenge comes from choosing which
ooze to kill so that your raid is faced with the least damaging combination of
abilities.

3.1. Raid Leader's Role

In this fight, the raid leader plays a preponderant role. Ordering the
raid to kill the right ooze and then giving the proper strategy for the
remaining two oozes is what the fight is really all about.

There is a lot of room for error, and killing the wrong ooze can
be easily recovered from if the right strategy is subsequently applied for
the remaining oozes.

4. Yor'sahj

4.1. Abilities

Void Bolt is Yor'sahj's only ability. This does a large amount of
Shadow damage to the tank, in addition to leaving a stacking Shadow damage
DoT. Yor'sahj uses this ability with a rather unpredictable frequency (on
average, every 5 seconds). The DoT deals damage (5,000 in 10-man difficulty
and 30,000 in 25-man difficulty) every 2 seconds, requiring two tanks
to swap the boss among themselves in 25-man difficulty. In 10-man, the damage
is easily healable.

Every 2.5 seconds, Yor'sahj also deals a moderate amount of damage with his
melee attack.

4.2. Summoning Oozes

Roughly every 75 seconds, Yor'sahj will summon 3 oozes of a different type
(out of 6 possible types) that slowly move towards him, doing nothing else. They
cannot be stunned or slowed. Upon reaching Yor'sahj, each one grants him a
different ability.

While the oozes are being summoned and while they are moving towards him,
Yor'sahj is immobile in the center of the room and does nothing, although he can
still be attacked.

Each ooze (also called globule) has a specific name. We will list these
names once (in the titles of the sections below), but we will refer to them by
their colour, as this is how the in-game emotes refer to them.

Your raid needs to kill one of the 3 oozes (doing so renders the other 2
immune to damage). This means that your raid will have to properly deal
with the buffs granted to Yor'sahj by the remaining 2 oozes. Failure to kill
one of the oozes will, most likely, result in a wipe.

5. Oozes: Abilities and How to Deal With Them

We will now present the oozes, ranking them according to the buff that they
give to Yor'sahj, from the most deadly to the least deadly.

5.1. Purple (Shadowed Globule)

This buff is not deadly on its own, but it creates a lot of confusion and
complicates the fight. Most raids will prefer the simpler strategy (even at the
cost of more raid-wide damage) that killing the purple ooze leads to.

The purple ooze grants Yor'sahj Deep Corruption. This ability does
a large amount of raid-wide Shadow damage (50,000 in 10-man, 55,000 in 25-man,
and 35,750 in LFR) for each fifth heal or absorb effect
that a player receives.

In case you encounter a combination with purple, the best way to deal
with Deep Corruption is to assign specific healers to heal the
damage. One healer (a Holy Paladin, preferably) should be assigned to
healing the tank, and other specific healers should
be assigned to healing damaged raid members (in the event that the other ooze
is red or green).

The aim is to keep the raid alive while casting as few heals as possible,
thus not triggering any damage from Deep Corruption.

It is interesting to note that certain heals do not trigger this effect.
We cannot provide a comprehensive list, but we will list those that we are
aware of:

5.2. Green (Acidic Globule)

In LFR, the buff given by the green ooze is considerably lessened, making
it one of the least dangerous. In 10-man and 25-man difficulties, however,
this ooze becomes much more problematic.

The green ooze grants Yor'sahj Digestive Acid. This causes Yor'sahj to
occasionally damage a random raid member and all allies within 4 yards of them
for a moderate amount of Nature damage (60,000 in 10-man and 25-man, and
39,000 in LFR). In LFR difficulty, the ability does not have an AoE
component.

Just like with the purple ooze, the buff given by the green ooze is not
deadly on its own, but it requires the raid to spread out when almost all the
other buffs require that the raid stacks.

The easiest way to deal with Digestive Acid is to have the raid
spread out at least 4 yards apart. This is generally not difficult, but may
be somewhat problematic when green is combined with another ooze that requires
the raid to stack, in which case you
will need to carefully spread out around the stacking location (the boss, most
of the time).

In LFR, spreading out is not necessary, and you can simply stack up and
heal any players damaged by Digestive Acid.

5.3. Yellow (Glowing Globule)

The yellow ooze grants Yor'sahj Glowing Blood of Shu'ma. This buffs
Yor'sahj, causing him to attack 50% faster and to use Void Bolt twice
as often. Additionally, it causes Void Bolt to have an AoE effect that hits
everyone in the raid (the DoT, however, is still only applied to the
tank).

In case your entire raid needs to stack together while the
Glowing Blood of Shu'ma is active (if you have red or black as the other
ooze), you should simply AoE heal the entire raid, and use damage reduction
cooldowns to facilitate this.

5.4. Black (Dark Globule)

The black ooze causes Yor'sahj to spawn a large number of adds, called
Forgotten Ones. These adds fixate on random raid members and regularly
cast Psychic Slice on them, which deals Shadow damage (35,000 in 10-man
and 25-man, 22,750 in LFR).

The best way to deal with the Forgotten Ones is to simply stack up
and AoE down the adds while healers use AoE heals to keep the raid alive.

5.5. Red (Crimson Globule)

The red ooze grants Yor'sahj the Searing Blood ability. This causes
Yor'sahj to damage a number of random players (3 in LFR and 10-man difficulty
and 8 in 25-man difficulty) for an amount of damage that is larger the farther
away from the boss these players are.

Note that Searing Blood appears to exclusively
target those players who are farthest away from Yor'sahj (and thus who take
the highest damage).

The best way to deal with Searing Blood is to have everyone as close as
possible to the boss (practically stacking on top of the boss). In case red
is paired with green (except in LFR), you will need to spread out 4 yards
apart around the boss.

5.6. Blue (Cobalt Globule)

The blue ooze creates a Mana Void. When this hostile unit spawns, it drains
the entire mana pool from all the casters in the raid. As it only drains mana once,
casters will start regenerating mana as normal and will still be able to cast
some spells. When the Mana Void is killed, it releases all the mana that it had
drained, distributing it evenly between all mana users within 30 yards (100
yards in LFR) of its location.

Dealing with the Mana Void is quite easy. Simply have all of your DPS
players switch to the Mana Void as soon as it is alive, killing it quickly.
This will restore mana back to all the casters, and from then on you can
continue the fight normally.

6. Strategy

In this section, we will provide you with all the relevant information for
succeeding in defeating Yor'sahj: which ooze to kill
and how to deal with the combinations of remaining oozes.

6.1. Start of the Fight

When Yor'sahj is not empowered by the abilities of any oozes, the encounter
is basically tank and spank. Healers must only be prepared to heal tank damage
(from melee swings and Void Bolt). This initial phase only lasts for 20
seconds.

The rest of the time, Yor'sahj will either be summoning the oozes
and doing nothing or be empowered with two additional abilities (or three, if
you failed to kill any of the oozes).

6.2. 6 Possible Ooze Combinations

While there are a total of 20 possible combinations, so far, only 6 have ever
been witnessed. So it is safe to assume that these are the only 6
combinations that the game will face your raid with:

black — blue — yellow;

black — green — red;

black — purple — red;

blue — green — purple;

blue — purple — yellow;

green — red — yellow;

6.3. Ooze Priority

Given that there are only 6 ooze combinations, the kill orders are
slightly different than what they would be if all 20 possible combinations
were present:

10-man/25-man: green > yellow > purple;

LFR: yellow > purple > black.

The kill priority specific to LFR difficulty comes from the fact that
the green ooze is almost harmless in LFR difficulty (due to
Digestive Acid not splashing to nearby allies).

6.3.1. Ooze Priority Addon

One of our readers had the great idea to write an addon called
Yor'sahj Automatic RaidWarnings.
This addon will give automatic raid warnings indicating which add should be killed,
using the kill order we gave in this guide. Note that the addon is currently
giving the LFR kill order by default, but this can be changed very easily by
modifying the Yorsahj Automatic Raidwarnings.lua
file (simply open it, the author left a lot of indications to help you modify the addon to fit your needs).

6.4. How to Deal With Ooze Combinations?

This section is not meant to be learnt by heart. By respecting the
kill priority, the strategy for handling the remaining two oozes
can easily be guessed from the buffs that they grant to Yor'sahj.
This section should mainly serve you when you are unsure about how
to handle a specific combination.

Combinations that cannot occur with our kill priorities are not
detailed. The first
section details combinations with the same strategies in all
difficulties. The second section details how to deal with
combinations specific to 10-man/25-man difficulties. The
third section details how to deal with combinations specific
to LFR difficulties.

6.4.1. Combinations With Common Strategies for All Difficulties

Black — Red

Blue — Purple

Black — Blue

6.4.2. Red/Yellow in 10-man/25-man Difficulties

Red — Yellow

6.4.3. Green/Red and Blue/Green in LFR Difficulty

Green — Red

Blue — Green

6.5. Tips

6.5.1. Tank Swap

Due to the high damage of the DoT left by Void Bolt in 25-man
difficulty (30,000 every 2 seconds, which, at high stacks can amount to as
much as 270,000 Shadow damage every 2 seconds), it is highly recommended that
you use two tanks. They should swap the boss among themselves whenever the
current tank has roughly 4 stacks of the DoT.

In 10-man and LFR difficulty, the damage of the DoT is much lower, so using
1 tank is entirely feasible (although it may be safer still to use 2 in
LFR).

Keep in mind that the DoT will stack fast when the boss has consumed the
Yellow ooze, when tank damage can sky-rocket.

6.5.2. Ooze Spawn Locations

The ooze spawn locations are fixed. They look like slightly elevated mounds,
found around the room, close to the wall. To have the highest uptime possible
on the ooze (thus ensuring that the designated ooze will die before reaching
the boss), players should run to the ooze spawn location as soon as the boss
begins channeling the new oozes.

Each ooze spawns from a mound that is (relatively) of the same color as
the ooze itself, making it easy to tell where to go. Note that the in-game
map of the room is misleading in this regard, and should not be used to
determine where each ooze spawns.

In order to make it easiest for DPS (especially melee) to run to the
correct ooze spawn point, the raid leader should set appropriately colored
raid markers, close to the center of the room, marking the directions of the
three oozes most likely to be killed by the raid (based on the above
priorities).

6.5.3. Using Heroism/Bloodlust

Heroism/Bloodlust/Time Warp should be used when the raid
can freely DPS the boss for a long time (such as after the Mana Void has
been killed in combinations that do not contain black).

7. Learning the Fight

The Yor'sahj encounter can be mastered rather easily, as long as the raid
leader is able to reliably call the correct ooze to be killed. The most
important piece of advice we can offer your raid is, thus, that you familiarise
yourself with the proper tactics.

Once the kill order is properly determined, your raid will only need to
execute some rather simple tasks (spread out, stack or DPS adds), that should
not pose any problems.

8. Heroic Mode

The only significant difference between the Heroic mode and the Normal mode
is that Yor'sahj will spawn 4 oozes instead of 3. Since you can only kill one,
it means that you will always have to deal with Yor'sahj being empowered with
the abilities of 3 oozes, instead of 2.

Other than this, all abilities deal more damage and all units (Yor'sahj, oozes,
adds, and Mana Void) have more health.

8.1. 6 Possible Ooze Combinations (Again!)

There is a total of 15 possible combinations. However, just like in Normal
mode, Blizzard made it so that we would only see 6 combinations:

black — blue — green — purple;

black — blue — green — red;

black — blue — purple — yellow;

black — green — red — yellow;

black — purple — red — yellow;

blue — green — purple — yellow.

8.2. Ooze Priority

The general ooze priority is yellow > green.

We believe that there should be two exceptions to it:

black — purple — red — yellow: kill purple instead of yellow,
this will enable you to heal through the extreme damage — though, with
a healing setup comprising several paladins (many of their spells do not
trigger Deep Corruption), it might be better to kill yellow and deal
with purple;

black — green — red — yellow; kill green instead of yellow, this will enable you to stack up on the boss and efficiently heal the extreme damage.

Additionally, for the black — blue — green — purple
combination, you can kill black instead of green. This will make your raid gain
precious DPS by not having to take down the adds, but your raid will have to
be properly positioned (otherwise, the healers might panic trying to heal
Digestive Acid, causing them to trigger Deep Corruption explosions).

8.3. Strategy

If you are attempting the Heroic version of this fight, then you should be
familiar with what the oozes do and how to deal with them. The fact that the
boss is buffed by 3 oozes does not add complexity to the fight. It looks as if
the possible combinations were carefully chosen so that you would have to
perform exactly the same variety of tasks as in normal mode: stack on the boss,
spread out, handle Deep Corruption, DPS the Mana Void, and DPS the
Forgotten Ones. What the third ooze invariably adds is more raid damage.

In any case, we will not delve further into the strategy part, as it is really
the same as in normal mode. The key to winning the fight is to properly handle
several things:

heal the extreme damage caused by having black,
red, and yellow
at the same time;

have the healers not blow the raid up when purple
is up;

strike a balance between attacking the boss and killing the various adds (oozes,
Forgotten Ones, and Mana Void), as we explain below.

Note that this combination can come twice or thrice in a row, meaning that
your raid should try to use AoE healing cooldowns sparingly, only when
necessary. This will enable you to survive the bad odds that come with
getting this combination several times in the fight.

8.3.2. Deep Corruption

Your raid will have to deal with purple
in half of the possible combinations (using our kill priority). This means that,
unlike in Normal mode, properly handling Deep Corruption is no longer
optional.

This debuff will stack on players every time they get a heal or receive an
absorb effect. At 5 stacks, the player will explode and deal a massive amount
of raid-wide damage.

To properly handle this debuff, healers must have it show in their raid
frame addons (the spell ID is 105171 and its name is Deep Corruption).

Also, purple is always up in combination
with blue, which deals no damage, and either of
black or green,
which deal very moderate damage. As you can see, purple is never combined with
a highly damaging ooze that would cause the healers to panic, so they should
be able to easily keep every player in the raid alive, without having to heal
them more than 4 times.

8.3.3. Beating the Enrage Timer

Most guilds progressing on Yor'sahj Heroic will find the 10-minute enrage
timer to be very tight. As we will explain in this section, precious seconds
can be saved in the way you will handle the oozes, the
Forgotten Ones, and the Mana Void.

Killing the oozes might not require the entire contingent of DPS. The
idea is to kill the ooze close to the boss, and not half-way through (which
would mean that some DPS that were sent to kill it would have been better
employed on the boss).

It takes the oozes approximately 23 seconds to reach the boss, from the moment
that they spawn. This means that you need about 110k DPS on the ooze in 10-man
difficulty and 360k DPS in 25-man difficulty. These values should be used to
determine exactly how many DPS should be sent to kill the ooze (some classes
can do high burst damage, take it into account).

When the Forgotten Ones spawn (something that happens in all combinations,
save one), DPS players should not specifically AoE them down. Rather, only
classes that can spread their damage on the boss to the adds (for example, Combat Rogues
with Blade Flurry, Fire Mages with Inferno Blast and Combustion)
or that can spread their damage on the adds to the boss (Enhancement Shamans with
Lava Lash,
Flame Shock, and Fire Nova) should bother with the Forgotten Ones.

Dealing with the Forgotten Ones in this way means that they will
remain alive longer, which increases raid damage (or tank damage, if the
tank managed to taunt them before they fixated on someone).

The idea is to survive with rather low mana for one phase or two, until you
get a second Mana Void (something that should happen quickly enough as 4 of the 6
combinations have blue). Then, as soon as the
second Mana Void has depleted all casters of their mana, the first Mana Void
should be killed. Hopefully it will be on low health, after taking a bit of
damage now and then.

After that, you should keep the second Mana Void as a means of re-filling
your raid's mana after the third Mana Void spawns and so on. All in all,
this will save you the trouble of killing one Mana Void. Since they
have a significant health pool, this will prevent you from wiping to
the enrage timer at 2% health.

Keep in mind that your raid can complete this achievement over the course
of several kills, as you do not need to experience all 4 combinations in a
single attempt.

From a strategy point of view, there is nothing complicated. Clearly,
whenever combinations arise where 2 of the 3 colors are a requirement for
the achievement, you will have to kill the 3rd color and survive the needed
2. In the case of Black and Blue, this is not problematic and you should use
the strategy listed above, in the relevant section.

For the other 3 combinations, we will provide summarised strategies.

9.1. Red and Green

For this combination, you must simply have the raid as close to the boss
as possible in order to take as little damage as possible from
Searing Blood, but at the same time be spread out at least 4 yards
apart.

This is not always easy, especially in 25-man difficulty. If faced with
a conflict, always prioritise spreading out over being slightly closer to
the boss.

9.2. Black and Yellow

This combination simply requires a lot of healing. Your raid should stack
up and AoE down the adds while healing through all the damage.

9.3. Purple and Yellow

This combination is arguably the most difficult. It requires your raid to
survive the rather massive amount of damage from Yellow, while healing as
little as possible, due to Purple.

You should also make sure that healing is kept to an absolute minimum, in
order to trigger as few explosions from Deep Corruption as possible. Players
should use any personal damage reduction cooldowns that they have.

10. Concluding Remarks

This concludes the encounter guide for Yor'sahj the Unsleeping. We hope you
will have fun performing this creative encounter. As long as you follow the
raid leader's instructions, the boss should not be too difficult to
overcome.